Conventionally, there has been used a vacuum processing apparatus for performing vacuum processing (e.g., film formation or etching) on a substrate such as a semiconductor wafer in a vacuum atmosphere. Further, there is known a so-called multi-chamber type vacuum processing apparatus, having a vacuum transfer chamber accommodating therein transfer mechanisms and a plurality of vacuum processing chambers which are provided around a periphery of the vacuum transfer chamber, for performing a vacuum processing on a substrate transferred to each of the vacuum processing chambers via the vacuum transfer chamber.
Such a vacuum processing apparatus includes at least a vacuum transfer mechanism provided in the vacuum transfer chamber and an atmospheric transfer mechanism provided in the atmospheric atmosphere. In order to increase the transfer efficiency, these transfer mechanisms are respectively provided with a plurality of picks capable of supporting a plurality of (e.g., two) substrates. Further, position alignment of these transfer mechanisms needs to be performed with respect to each of the access points.
As for such an position aligning method, there is known a method including: performing with the naked eyed rough position alignment (rough teaching) with an accuracy just enough to enable each of transfer mechanisms to transfer a substrate; transferring the substrate to each access point by a transfer mechanism; and performing precise position alignment by detecting positional displacement of the substrate by a substrate position detecting mechanism (orienter) provided in the atmospheric atmosphere (see, e.g., Patent Reference 1).
Namely, in this position aligning method, the substrate is transferred from an access point (e.g., a load lock chamber) to the orienter by the atmospheric transfer mechanism provided in the atmospheric atmosphere, so that the displacement of the substrate is detected. By correcting the displacement, the delivery position of the atmospheric transfer mechanism with respect to the access point is aligned. Next, the substrate transferred to the load lock chamber by the aligned atmospheric transfer mechanism is taken by the vacuum transfer mechanism provided in the vacuum transfer chamber, and then is transferred to, e.g., another load lock chamber adjacent thereto. Thereafter, the substrate is transferred to the orienter by the atmospheric transfer mechanism again, so that the displacement of the substrate is detected. As a consequence, the delivery position of the vacuum transfer mechanism is aligned.
In the above prior art, a delivery position of the vacuum transfer mechanism provided in the vacuum transfer chamber is aligned by the single substrate position detecting mechanism (orienter) provided in the atmospheric atmosphere. To do so, the substrate aligned by the orienter is transferred and disposed at the load lock chamber by the atmospheric transfer mechanism. Thereafter, the substrate is transferred by the vacuum transfer mechanism, and then is taken by the atmospheric transfer mechanism again. Next, the substrate is transferred to the orienter, so that the positional displacement is detected. As a consequence, a transfer distance of the substrate to the orienter becomes long and, also, errors of delivery position coordinates of the access points (load lock chambers or the like) to which the substrate are delivered are accumulated. As a result, the accuracy of the delivery position coordinates deteriorates.
Patent Reference 1: Japanese Patent Laid-open Application No. 2004-174669